doc: Update onion service target port numbers in tor.md

Summary:
This is a backport of core#19991 [8/8]
https://github.com/bitcoin/bitcoin/pull/19991/commits/96571b3d4cb4cda0fd3d5a457ae4a12f615de82b

Depends on D10450

Test Plan: proofreading

Reviewers: #bitcoin_abc, majcosta

Reviewed By: #bitcoin_abc, majcosta

Differential Revision: https://reviews.bitcoinabc.org/D10451